TY once again Muggs.
The version shown; to me mechanically employs as like an Awning Hitch Lesson#1854/pg.310 in
tinyurl.com/abok-online. Shows as kicking to trigger release for that use. Seen this as you show for farmers and truckers, where the eye can be set higher than normal reach in loading, to then be able to undo from ground when out of reach at delivery from over a load quick/clean/go git another load... Trailer/Truck bed may have small hooks ready, instead of carabiner. Good to slap line as if to sweat Zrig side in making, to equalize force across top and opposing side. If don't, may self equalize thru travel vibrations to all around looser than tightened.
For our usages, many times a self tending Prussic can be truly magical addition to maintain 'purchase'(ABoK) of pulled rope to reserves of slack bank. Without safety Prussic reserve/banked line can also be paid out/drawn from to lower, until overdrawn/bankrupt/crash..
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Another trick is to put that Round Turn crossed on self; inside the eye too and when get it right can pull and self locks for light /temp duty in similar Awning Hitch fashion. This Awning strategy of crossed instead of regular Round Turn subtlety defines Lesson#1855 MidShipMan's Hitch (Awning/crossed) vs. #1866 Rolling Hitch(Round Turn not crossing self). #1877 again reminds more of a reverse 'Cow' type finish at end gives anti-torque in knots(rather than continuous direction torqueing and also harder untie). Taking these as lessons/recipes, can find 1 'spice' and bring or see in another place like this.
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The input of Zrig runs faster, over longer range than the output; as this is a converter like a gearbox ; where also reversing system can get load to move over more distance in same time for faster/but can't pull as much. Have used for pulling up hills from truck on top, but not enough run for truck, but truck(my mule) has more power than needed for task. To this view, systems simply swap velocity and force, as like transmission; where motor is called 'power plant' with narrow powerband made wider to usage, just as doing here with Zrigs etc. from finite , narrow powerband of hand pull. Zrigs have 1x,2x,3x positions exposed, can rotate which is input, output, anchor to extrude different effects. These are all mechanics we manufacture on the fly, in rope. Other materials might end up drilling, grinding, melting, pounding etc. for days to make power and/or speed leveraging tools, then there is rope, so deceptively simple !
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3x3=9, iff input is inline and then less friction. (iff='if and only if' logics abbrev.)
This is for adding 1 system on another, serially/daisy chain like.
But, can inset, so inner system pulls on outer from 2 not 1 input positions, using the inner system force usually 'wasted' on to an anchor(not pulling on load), instead made to be a 2nd input (of lesser value) inside other system, to greater output of force, but less speed per "trade laws".
Doing this just with hands at proper points on Zrig gives 4x effort potential against load now !
>>then inset that in another !
Note when a system is totally 'closed circle' , both hands used as shown; the 2x and 3x outputs of Zrig on anchor and load, now are BOTH 4x; which can be double edged sword of both curse and/or gift in scenario as upgrade anchor pull from 2x to 4x; but then ca also inset that inside another system !
Whenever get as iron rigid as can, by whatever method, for last impact pulse can shear across the made rigidity as if to sweat/swig; the response will be high amplitude. The more rigid made the rope tightened first linearly/along it's length , the less rubbery response back from the leverage on the iron like stiffened rope sheared across it's length with force.
The turn/trap comes out/unhooks self from Sheepshank i think, as does Bowline when too much freedom/not stiff enough against not coming out/unhooking the input/output legs in the Half-Hitch (continuous form) and destabilizes at first opportunity i think.
The actual subject of this pic is another pruf to me of force in straight lines, prefers to even skip loop when can as 2nd drawing in above pic.
Eye would make think more force goes thru curve than skips curve(1st drawing in pic above); i don't think that is true-est.
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How i try to approach new theories: